At least 16 deaths have been blamed on a winter storm that dumped nearly 2ft of snow in finger-numbing temperatures in parts of north-east America.
Light, fluffy snow meant an easier time digging out than it might have been and the storm caused just a few thousand power cuts. But the bone-chilling cold could mean a risk of frostbite for anyone who spends more than a few minutes outside.
Wind chills around New England were reported as low as minus 20 degrees Fahrenheit and forecasters warn it could be just as bad today.
Temperatures in the north east are expected to rise above freezing this weekend before the arrival of another blast of frigid air already affecting the Midwest.
As motorists and homeowners in the east began digging out of the snow and ice, states from the upper Midwest to New England were preparing for another arctic blast over the next few days that could be even worse.
About 2,200 flights were canceled nationwide, according to aviation tracking website FlightAware.com. Most were in New York, Philadelphia, Boston, Chicago and Washington DC.
Governors in New York and New Jersey declared states of emergency, urging residents to stay at home. Hundreds of schools were shut down in Boston and New York, extending the holiday break for tens of thousands of students.
"This is nothing to be trifled with," New York governor Andrew Cuomo said. "People should seriously consider staying in their homes."
The heaviest snow fell north of Boston in Boxford, Massachusetts, which received nearly 2ft. Nearly 18ins fell in Boston and in western New York near Rochester. New York's Central Park and Philadelphia each got 6ins.
Slick roads have caused traffic deaths in Michigan, Kentucky, Indiana and Illinois.
A massive pile of salt fell on a worker at a Philadelphia storage facility, killing him. And authorities say a woman with Alzheimer's disease froze to death after she wandered away from her rural New York home.
Another wave of cold air already was moving through the Midwest after coming down from Canada.
Outreach teams were searching streets in New York City and Boston for homeless people at risk of freezing to death.
Some major highways in New York state were shut down overnight and commuter trains around New York City were operating on a reduced schedule.
New Jersey governor Chris Christie ordered non-essential state workers to stay home.
The heavy weather began rolling in on Thursday, just a day after New York mayor Bill de Blasio was sworn in to lead the nation's largest city.
Mr De Blasio, who in 2010 criticised predecessor Michael Bloomberg for his handling of a post-Christmas storm, said 1,700 snow ploughs and 450 salt spreaders hit the streets.
"I feel great about the response," Mr De Blasio said after shovelling the pavement outside his Brooklyn home.